We are conducting a coordinated program of neurophysiological, neuroanatomical, endocrinological and biochemical research on the sensory and hormonal basis of olfactory discrimination in mammals. The objectives of the research include (1) chemical identification of biologically active constituents in pheromonal secretions, (2) study of the mechanisms and neural pathways by which these substances affect neuroendocrine and reproductive functions, and (3) characterization of the mechanisms and pathways by which changes in hormonal secretion influence the neural processing of biologically relevant stimuli.